Our Top Ford Spark Plug Thread Repair Kits

DennisB, WiseAutoTools.com ©

Looking for the best repair for your blown out spark plug? One that can be done without removing the cylinder head? You've come to the right place. In just a few minutes we'll give you the rundown on the best solutions for Ford spark plug thread repairs, even the largest oversize repairs. All of our repairs use the original spark plug when completed.

Every day, we receive calls from customers looking for a reliable solution for spark plug holes that have failed previous repairs. While we offer kits for various car makes, Ford vehicles commonly experience spark plugs blowing out. Often, vehicle owners and repair shops opt for quick, inexpensive fixes from local stores. Although this approach is quick, it doesn’t always offer a lasting solution and might cost more in the long term. Since 2005, we've been providing quality thread repair kits that ensure durable repairs for Ford vehicles.

The Big Solution: Time Sert 5553

One of our most popular items is the Time Sert 5553 kit, featuring a sturdy insert measuring 0.68″ across the thread’s outer edge—much more substantial than the average wire coil or thin insert. Known as the Big Sert, this kit can handle previously failed repairs due to its robust design. The Big Sert stays secure through a combination of a locking pin, Loctite, and a unique self-locking design achieved by cold rolling during installation. This process expands the insert’s bottom, securing it firmly in place. Our customers frequently praise this kit for its effectiveness.

The Bigger Option: Calvan 38900

For specific Ford models from around 1998 to 2019, the Calvan 38900 is an excellent choice. It fits 2-valve engines in models such as the 4.6, 5.4, and 6.8 but isn't suitable for DOHC engines. See our product listing for more details on what this works on. The Calvan 38900’s insert is slightly larger at 0.73" in diameter, offering a tighter seal. It uses JB Weld under the lip and thread locker for the exterior threads for securing. It features a shoulder/lip at the top of the insert which tightens against the contact surface, similar to a bolt head.

The Even Bigger Repair Solution: Time Sert 5600

When you need a larger OD, the Time Sert 5600 is a common go-to. It’s one of the the largest Ford thread repair kit available, capable of installing an insert within an insert, expanding the outer diameter to .77". This size is needed for severe cases where other inserts have failed or there’s a compression leak around the insert. The 5600 is ideal for substantial repairs without the need for replacing the cylinder head.

The Biggest Thread Repair Kit - We also offer a new addition for 2024, the 389XL kit. OK this one is new to our line-up and is slightly larger than the 5600! This kit is slightly larger than the 5600, measuring at 0.78" in diameter. It's a more affordable alternative when the largest repair is necessary. The 389XL uses a single insert and includes a guide for easy alignment.

Words of caution: There has recently been a lot of kit's that look similar to the 38900 kit. The quality of the kits are questionable to say the least. It's good to know that we quality inspect all tooling and inserts before shipping so our customers don't have any problems. In addition to the manufacturer's instructions, we also provide free tips that answers common questions. The same cannot be said for kits sold on Amazon and eBay. See our previous article for more info on that.

Also there's an individual selling a 7/8" OD insert on eBay for a huge hole repair. However, engineers have determined that that is way too big for safely repairing Ford 4.6, 5.4 and 6.8 cylinder heads. There simply is not enough metal around the valves for this to be a dependable repair. The largest repair that can be done safely is the 389XL which measures right at 20mm. 

Since 2005, we've been dedicated to providing expert solutions for thread repair. Need assistance in selecting the ideal thread repair kit for your specific situation? Reach out to us at 800-734-8665 ext. 251 or simply fill out our Contact Form. Your query might even inspire an article on optimizing thread repair methods!